System for combining a plurality of pulses into a single pulse train

ABSTRACT

A system for receiving pulses from a plurality of devices which measure a quantity such as fluid flow and for storing separately the pulses from each such device in individual storage elements. The individual storage elements are sequentially interrogated to provide output pulses onto a common output line from the elements which are storing pulses.

United States Patent Inventor Theodore Parker Findlay, Ohio Appl. No.729,969

Filed May 17, 1968 Patented Nov. 2, 1971 Assignee Marathon Oil CompanyFindlay, Ohio SYSTEM FOR COMBINING A PLURALITY OF PULSES INTO A SINGLEPULSE TRAIN 3 Claims, 2 Drawing Figs.

U.S. Cl 340/150, 340/183 Int. Cl H04q 9/00 Field of Search 340/ 147,

[56] References Cited UNITED STATES PATENTS 3,144,046 8/1964 Seesselberg340/239 X 3,500,132 3/1970 Garrett 340/239 X 2,937,369 5/1960Newbo1detal.... 340/183 X 3,132,329 5/1964 Penser 340/183 3,312,9664/1967 Schaller 340/239 Primary ExaminerDonald J. Yusko Attorneys-JosephC. Herring, Richard C. Wil1son,.lr., Jack L, Hummel and Sughrue,Rothwell, Mion, Zinn & Macpeak ABSTRACT: A system for receiving pulsesfrom a plurality of devices which measure a quantity such as fluid flowand for storing separately the pulses from each such device inindividual storage elements. The individual storage elements aresequentially interrogated to provide output pulses onto a common outputline from the elements which are storing pulses.

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sum 1 0F 2 L ii INVENTOR THEODORE PARKER 23 OUTPUT RELAY 5 1 M M 1 I 24BY 2M. 4 a.

ATTORNEYS RATENTEU NUVZ l9?! SHEET 2 0F 2 SIZ-I 3l-l\ 33 METER S 6 MsAND R o |2-2 m METER V S 6 V "5 AND V R o 34\ SCANNER 3|-3 333 2-3 4 7 S6 7 MS METER 3H F F LAND R Q 12-4 R 334 METER 7 S v a MS 32-4 F F I ANDR Q INVENTOR THEODORE PARKER SW,W ML BY TM ATTORNEYS SYSTEM FORCOMBINING A PLURALITY OF PULSES INTO A SINGLE PULSE TRAIN BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention relates to asystem for receiving, from a number of individual measuring devices,pulses which represent the amount of some quantity measured, and forcombining the information represented by the pulses into a single pulsetrain. 2.

Description of the Prior Art Some prior art systems have used analogmeasurement signals as inputs to a multiplexing arrangement. Othersystems which have combined pulses from a'riumber of sources have merelytaken the pulses at the time they were generated and combined them, withthe resulting possibility of two coincident pulses being combined toappear to be one pulse. Other systems have provided analog or quantizedanalog summations of measurement pulse signals.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is acircuit diagram of the preferred embodiment of the invention, usingbistable relays as storage devices. I

F IG. 2 is a block diagram illustrating one of the many possible ways ofconstructing a solid-state circuit embodying the principles of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates anelectromechanical embodiment of the invention.

A disc 1, which may be of some plastic material, is arranged to berotated at some angular velocity (150 revolutions per minute in thepreferred embodiment) by a motor 2. Mounted on the periphery of thisdisc is a magnet 3 for rotation with the disc. A suitable nonmagneticcounterbalance may be provided if desired. Four reed switches, 4-1, 4-2,4-3 and 4-4, are shown mounted in a fixed position relative to theperiphery of the disc. As the magnet passes each reed switch, it causesthat switch to close for a brief instant. This combination of motor,disc, magnet and switches comprises an electromagnetic scanner. Abattery 5, or any other such power source, is connected at its negativeterminal to ground and at its positive terminal to one terminal of eachof the four illustrated reed switches.

Throughout this specification, four elements for four channels will beshown and described. This is for convenience of illustration only, and agreater or smaller number could be used with obvious modifications.

Assuming that switch 4-1 has just been closed, a pulse of current willpass through the switch and activate coil 6 of bistable relay 13-1. Thisrelay is of a type similar to relays 13-2, 13-3 and 13-4 and may be ofthe type marketed by C. P. Clare as a bistable mercury relay HGS-ll9,C". Other such relays or their equivalents could also be used. A currentpulse through coil 6 will cause relay arm to move into contact withcontact 16. If arm 15 is already in contact with contact 16 at the timeof the current pulse through coil 6, there will be no change in the armposition. Because the relay is bistable, arm 15 will remain in contactwith contact 16 until changed by current through coil l1.

Elements 12-1, 12-2, 12-3 and 12-4. are separate but similar measuringdevices. In the preferred embodiment these devices are used to measurethe flow of some fluid through a conduit and to provide a pulse outputfor each .unit of fluid flow measured. Other quantities could also bemeasured to provide pulse outputs. In element 12-1, a flow metermeasures the flow of fluid and closes, then quickly opens, a switch 8,each time a unit of fluid has passed. Such metersarewell known in themeasuring art. When switch 8 closes and opens, a currentpulse fromresistor 9 and power supply 10 passes through switch 8 and throughbistablerelaycoil 11 inrelay unit 13-1. A current pulse through coil 11will cause relay arm 15 to move into contact with contact 17. If arm 15is already in contact with contact 17 atthe time of the current pulsethrough coil 11, there will be no change in the-armposition. Note,however, that this latter condition is impossible in a properlyfunctioning device according to the present invention.

With the device in operation, if. the meter 7-has recorded a measuredunit since the bistable relay 13-1 was last interrogated by reed switch4-1, arm 15 will be in contactwith contact 17. If not, the arm will bein contact with contact 16.

If the bistable relay is storing a unit measurement when interrogated,the movement of arm 15 against contact 16 causes a pulsed relay-unitoutput current to flow frompower supply 18 through capacitor 19 anddiode 21 onto common line 26. This relay-unit output current continuesuntilthe capacitor is charged, then stops.

The .next measured-unit indicating pulse moves arm 15 down to contact17, causing capacitor 19 to discharge through resistor18 to prepareforthe next interrogationpulse.

Elements 18, 19, 20 and 21 are illustrated in block 14-1.

Blocks l4-2, 14-3 and 14-4 are similar to 14-1. I The pulsesenteringcommon line 26 pass through relay coil 22 and resistor 23 to ground. Theappropriate relay arm, contacts, and power supply means can be includedin relay unit 24 to produce the desired total measurement pulsesinoutput 25.

The scanning speed of the scanner unit is arranged to be greater thanthe maximum expected pulse rate of any one flowmeter. If a pulse is instorage at the moment of interrogation, the bistable relay will changestatus, causing an output pulse onto line 26. If no pulse is in storageat'the moment of interrogation, the bistable relay remains stationary,maintaining the established charge on the capacitor and producing nofurtherrelay-unit output pulses.

Because the electromechanical scanner provides sequential interrogationof the individual storage circuits, incoming pulses are systematicallytransferred to the output circuit preventing the loss of simultaneousinput pulses. If an input pulse is applied to a storage circuit at themoment of interrogation, the bistable relay will be controlled by theincoming pulse due to its higher current. If this situation were allowedto occur during two consecutive scans, a pulse would be lost. Since ithas been specified that the scan rate must be faster than the fastestflowmeter pulse rate, the foregoing condition cannot occur; therefore,no pulses will be lost.

The size of the capacitor in the storage circuit is such that its chargetime will allow the output relay to operate fully and drop out againprior to the interrogation of the next storage circuit.

FIG. 2 illustrates one of many possible ways in which the inventiondisclosed in FIG. 1 can be constructed in an all-electronic manner.

The same pulse producing meters 12-1, 12-2, 12-3 and 12-4, as disclosedin FIG. 1, provide the measurement pulses. The pulses are furnished tothe set input terminals S of setreset flip-flop 31-1, 31-2, 31-3 and31-4. Such set-reset flipflops are well known in the art and have thefunction described on page 18-03 of Handbook of Automation. Computationand Control, Vol. 2, John Wiley & Sons, I959. The following truth tablegives the outputs 0+1 and Q+l for inputs S and R where the immediatelyprevious outputs were 0 and o o o 6 l I Unknown Unknown A scanner 30,which may be equivalent to the previously described scanner havingelements 1, 2, 3, 4-1 through 4-4 and 5, or which may be, for example, aperiodically pulsed ring counter, provides successive pulse outputs fromterminals 1, 2, 3 and 4.

An AND-gate such as 32-] is connected to receive the scanner outputpulse, such as that from terminal 1, and to receive the Q output fromits associated flip-flop. If the last previous input pulse to theflip-flop was received on the set terminal S from meter 12-1, theoutputs Q and 6 were left respectively as I and 0 corresponding to thethird line of the table. This condition of Q=l causes the AND gate to beopen to scanner pulses when they occur.

A scanner pulse to reset terminal R causes output 6 to go from 0 to l,triggering monostable circuit 33-1 to give a pulse output to OR circuit34.

When Q=0, indicating that the last input pulse was received by resetterminal R, the AND-gate 32-1 is closed and will not allow the resetterminal to be triggered. This eliminates the possibility that thecondition shown on line 4 of the table could exist. if the set terminal5 receives a pulse, even if coincident with a reset pulse, the setcondition will prevail until a reset pulse is received after theflip-flop is set.

Although only one channel has been described, the other channels aresimilar-and also apply their outputs to the input of OR-gate 34. OR-gate34 passes all pulses received to form a pulse train at the output.

Many more examples of the application of the present invention willsuggest themselves to those skilled in the art. Alternative methods ofaccomplishing the invention may suggest themselves to those skilled inthe art. Accordingly, the scope of the present application is limitedonly to the extent of the claims which follow.

lclaim:

l. A system for totalizing pulses from a measuring devices, comprising:

a. a plurality of quantity measuring devices each producing a pulse perunit ofmeasured quantity, b. an equal plurality of bistable elementseach having first plurality of quantity and second stable states,

c. an equal plurality of setting means each associated with a bistableelement and responsive to a pulse from an associated measuring devicefor setting the bistable element to its first state,

d. an equal plurality of interrogation means each associated with abistable element,

e. scanning means for successively supplying pulses to each of theinterrogation means at a predetermined rate, said scanning meanscomprising:

1. means for moving a magnet about a closed path,

2. a plurality of biterminal switch means situated about said closedpath and each adapted to be closed by said magnet when said magnet movesin the vicinity of the switch means, and

3. a source of potential connected to one of the terminals of eachswitch means, the other terminals of the switch means being connected tosupply pulses at a predetermined rate,

f. each interrogation means being responsive to a pulse from thescanning means for resetting its associated bistable element to itssecond state,

g. an equal plurality of output pulse means each responsive to thetransition of an associated bistable element from its first state to itssecond state for generating an output pulse, and

h. means for combining all of the output pulses, at their relative timesfor occurrence, into a single pulse train.

2. A system according to claim 1 wherein: a. each said bistable elementcomprises the arm and contacts of a bistable relay,

b. each said setting means comprises a first coil of said associatedbistable element, and

c. each said interrogation means comprises a second coil of saidassociated bistable element.

3. A system according to claim 2 wherein said means comprises:

a. a source of potential,

b. a capacitor having two terminals,

c. means responsive to said interrogation means for connecting oneterminal of said capacitor to said source of potential for producingsaid output pulse at the other terminal, and

d. means responsive to said setting means for discharging saidcapacitor.

output pulse

1. A system for totalizing pulses from a plurality of quantity measuringdevices, comprising: a. a plurality of quantity measuring devices eachproducing a pulse per unit of measured quantity, b. an equal pluralityof bistable elements each having first and second stable states, c. anequal plurality of setting means each associated with a bistable elementand responsive to a pulse from an associated measuring device forsetting the bistable element to its first state, d. an equal pluralityof interrogation means each associated with a bistable element, e.scanning means for successively supplying pulses to each of theinterrogation means at a predetermined rate, said scanning meanscomprising:
 1. means for moving a magnet about a closed path,
 2. aplurality of biterminal switch means situated about said closed path andeach adapted to be closed by said magnet when said magnet moves in thevicinity of the switch means, and
 3. a sOurce of potential connected toone of the terminals of each switch means, the other terminals of theswitch means being connected to supply pulses at a predetermined rate,f. each interrogation means being responsive to a pulse from thescanning means for resetting its associated bistable element to itssecond state, g. an equal plurality of output pulse means eachresponsive to the transition of an associated bistable element from itsfirst state to its second state for generating an output pulse, and h.means for combining all of the output pulses, at their relative timesfor occurrence, into a single pulse train.
 2. a plurality of biterminalswitch means situated about said closed path and each adapted to beclosed by said magnet when said magnet moves in the vicinity of theswitch means, and
 2. A system according to claim 1 wherein: a. each saidbistable element comprises the arm and contacts of a bistable relay, b.each said setting means comprises a first coil of said associatedbistable element, and c. each said interrogation means comprises asecond coil of said associated bistable element.
 3. a sOurce ofpotential connected to one of the terminals of each switch means, theother terminals of the switch means being connected to supply pulses ata predetermined rate, f. each interrogation means being responsive to apulse from the scanning means for resetting its associated bistableelement to its second state, g. an equal plurality of output pulse meanseach responsive to the transition of an associated bistable element fromits first state to its second state for generating an output pulse, andh. means for combining all of the output pulses, at their relative timesfor occurrence, into a single pulse train.
 3. A system according toclaim 2 wherein said output pulse means comprises: a. a source ofpotential, b. a capacitor having two terminals, c. means responsive tosaid interrogation means for connecting one terminal of said capacitorto said source of potential for producing said output pulse at the otherterminal, and d. means responsive to said setting means for dischargingsaid capacitor.